Machine for bending sheet metal shapes



July 7, 1931. A. RAFTER 1,812,982

MACHINE FOR BENDING SHEET METAL SHAPES Filed Dec. 13. 1929 2 Sheets-Sheet l July 7, 1931. A. RAFTER MACHINE FOR BENDING SHEET METAL SHAPES I Filed Dec- A I w Ill/ll TTOR Patented July 7, 1931 UNITED STATES PATENT- OFFICE ALBERT RAI'TER, F BELLEVILLE, N E'W J E R SEY, ASSIGNOR TO RAFTER MACHINE COM- rangement of PANY, OF BELLEVILLE, NEW JERSEY, A

RAF'I'ER AND JOHN C. RAFTER, JR.

PARTNERSHIP COMPOSED OF ALBERT MACHINE FOR BENDING SHEET METAL SHAPES Application flled December 13, 1929. Serial No. 413,770.

This invention relates to a bending machine adapted for shaping wide sheets'of metal of any length.

The usual bending machines are capable of accommodating narrow stri s of metal of any length, or wide sheets 0 metal of a length depending upon the distance between,

certain elements of the machine.

Heretofore, open-face machines have been produced to enable the bending of wide sheets of metal of any length, but in order to accomplish that result it has been necessary to provide exceptionally large and heavy elements, and huge supports extending from the top of the machine to points at a considerable distance from the base of the machine.

Obviously, such a construction produces an inconveniently wide and bulky machine in which the connecting rods for actuating the hammer are subjected to enormous transverse stresses which in a short time result in the destruction of important elements of the machine.

It is an object of this invention to provide an open-face bendin machine adapted to shape wide sheets of metal of any length, said machine bein considerably narrower, lighter, and less bul than existing machines of a similar type delivering the same force of blow by a hammer during the bending operation.

A further object is to provide in a bending machine a htmmer actuating connecting rod which requires no guides and which is not subjected to the damaging effects of side stresses.

A further object is the provision of convenient and, efficient means for adjusting the hammer relative to the connecting rod.

These and other objects are attained by the novel construction,combination and ararts hereinafter described andshown in t e accompanying drawings,

constituting a material part of this disclosure and in which Figure 1 represents a front elevational view of the bending machine.

Figure 2 represents an end elevational view of the machine.

Figure 3 represents asectional view taken on the line 3-3 of Figure 1, Figure 4 represents a rear view of a portion of the end of the machine.

- Referring to the drawings, a bending machine of the open-face type is shown to have a bed 5 adapted to support a female die.

Mounted on the rear of the bed is a gearing arrangement adapted to receivepower from the electric motor 6 and deliver it to the large nalled the stub shafts 13 and 13' integral with an internally threaded nut 14 in ment with a screw 15.

The screw 15 is provided with a flange 16 which rests upon the bar 17 integral with the hammer 18. Above the flange 16 the screw has a reduced portion to which is fixed a worm gear 19 in mesh with a worm 20, by means of which the hammer may be adjusted relative to the nut 14:. A nut 21 holds the worm gear 19 securely in position. The Worm and worm gear are housed in a casing 21' which is secured by bolts to the bar 17.

Mounted upon the bed 5 is an upwardly extending guide bracket 22 having guide flanges 23 and 25. The hammer has integral therewith the pads 23' and 24', to which are attached the angles 23a, 25a and 24a, 26a, respectively, the flan cs '23 engaging angles 23a and 24a, while flange 25 engages angles' 25a and 26a.

engage- By means of this arrangement the hamscrew 15 engage parts of casing 21' to lift the hammer, the latter being connected to casin 21 by means of bolts.

11 the down or bending stroke, the flange 16 on screw 15 bears against bar 17 to force the hammer downwardly.

Now, during the bending operation there are present side stresses which would have a destructive effect upon the connecting rod and other parts of the machine, were not means provided to compensate for such stresses.

In my machine, it will be noted that the connecting rod is pivotally connected with the nut 14, and conse uently the side stresses are compensated for y causing the connecting rod 10 to rotateslightly relative to nut 14.

The amount of rotation is slight since the distance between shaft 8 and shafts 13 and 13' is about sixty inches while the stroke of the hammer is about three inches. However, the force of the blow is enormous, amounting to about 300,000 pounds and the rotation of connecting rod 10 on shafts 13 and 13 is of great importance.

It is obvious that my connecting rods need no guides, and the hammer only is guided. Since the path of the hammer is essentially linear, guides therefore may be simply and conveniently attached to and extend upwardly from the bed itself.

The guides are not required to absorb enormous slde stresses and consequently no particular attention need be pad to their size and strength.

From the above description it will be seen that I have produced a simple bending machine of relatively light weight, and which occupies an unusually small amount of space for the enormous forces it is-"intended to exert. My arrangement of the connecting rods leaves the ends and the front of the machine open so that wide sheets of material of any length may be bent.

When it'is desired to adjust the stroke of the hammer, the shaft 26 is rotated by any suitable means to rotate worms 20 and worm gear 19, which cause the rotation of screw 15.

Since longitudinal movement of the latter is prevented relative to the hammer and nut 14 is stationary during the adjustment, the hammer and screw move together and their position relative to the connecting rod 10 is thus ad'usted.

The oregoing disclosure is to be. regarded as descriptive and illustrative only, and not as restrictive or limitative of the invention, of which obviousl an embodiment may be constructed inclu ingmany modifications without departing from the general scope herein indicated and denoted in the appended claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a bending machine, a bed, a hammer, a connecting rod having an arm adjustably connected with the hammer, said .arm being directed at an angle to the line of travel of the connecting rod'and eccentric means mounted on the bed for reciprocating the connecting rod.

2. In a bending machine, a bed, a hammer, a connecting rod having an ofiset portion at its upper end pivotally connected with the hammer, said connecting rod having an oliset portion at its lower end, and eccentric means mounted on the bed and associated with the" lower offset portion of the connecting rod for reciprocating the latter.

3. In a bending machine, a bed, a hammer, a screw mounted on the hammer for rotary movement only, an internally threaded nut in engagement with the screw, stub shafts projecting from the sides of the nut, a connecting rodhaving at its upper end a forked offset portion rotatably connected with the stub. shafts, said connecting rod having an offset portion at its lower end, and eccentric means mounted on the bed and associated with the lower offset portion of the rod for reciprocating the latter.

4. In a bending machine, a bed, a hammer, a U-shaped connecting rod having one leg pivotally connected with the hammer, and eccentric means on the bed rotatably connected with the other leg of the connecting rod to reciprocate the latter.

5. In a bending machine, a bed, a hammer, means attached to the bed to guide the hammer, a screw rotatably mounted on the hammer, means associated with the hammer to prevent longitudinal movement of the screw, a nut in threaded engagement with the screw, a U-shaped connecting rod, means for pivotally connecting the upper leg of the rod to the nut, and eccentric means rotatably connected with the lower leg of the connecting rod to reciprocate the latter.

6. In a bending machine, a bed, a hammer, a screw rotatably mounted on the hammer, a nut in threaded engagement with the screw,

a U-shaped connecting. rod having its upper legpivotally connected with the nut, means associated with the lower leg of the rod to reciprocate the latter, a worm wheel fixed to I a reduced portion of the screw, a worm in engagement with the worm wheel, a casing for the worm wheel and worm, said casing being fixed to and cooperating with the hammer to prevent longitudinal movement of the screw, and means for rotating the worm whereby the hammer may be adjusted relative to the connecting rod.

This specification signed this 11th day of December, 1929.

- ALBERT RAFTER. 

